The electrical treatment of scaphoid nonunion.

Seventy-one percent (12 out of 17) of the previously treated nonunions united within 12 weeks by a semi-invasive technique of electrical stimulation. The electrodes are stainless steel and Teflon-coated except for the 1 cm bare tip. The power source is a 7.5 volt battery in circuit with resistors and transistors such that a constant continuous current of 20 muamp is applied to each electrode. Three or four cathodes are implanted percutaneously, using local or regional anesthesia with radiographic control, usually an image intensifier. A long-arm cast is used for three weeks and then reduced to a short-arm cast which is used for nine additional weeks. The indication for this technique is failure of previous bone grafting. The contraindications are wrist arthritis and an avascular proximal pole. Patient acceptance of this electrode technique was high and morbidity was less than in those patients treated by iliac bone grafting. The treatment of nonunion of the scaphoid by this semi-invasive electrical stimulation technique is a reasonable alternative to bone grafting and provides a salvage procedure when bone grafting or other therapeutic modalities have failed.